Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4880065 | Air motor operated rotary earth drilling tool | William J. McDonald, Michael R. Wasson, Curtis E. Leitko, Jr., William C. Maurer | 1989-11-14 |
| 4858704 | Guided earth boring tool | William J. McDonald, William C. Maurer, Michael R. Wasson, William Christian Herben | 1989-08-22 |